The epidemiology of retinal reticular drusen

Extensive macular atrophy with pseudodrusen-like appearance: comprehensive review of the literature

PURPOSE

This review focuses on extensive macular atrophy with pseudodrusen-like appearance (EMAP), a recently described maculopathy presenting with pseudodrusen-like lesions and chorioretinal atrophy more pronounced in the vertical axis.

METHODS

Narrative review of the literature published until May 2024.

RESULTS

The early onset age of EMAP (50-55 years) and its distinctive natural history, which includes night blindness followed by severe vision loss, differentiate it from atrophic age-related macular degeneration (AMD). A clear pathogenesis has not been determined, but risk factors include female gender and complement system abnormalities (altered levels of C3 and CH50). Moreover, lifelong exposure to pesticides has been suggested as risk factor for direct neuronal degeneration involving rods and cones. In the early phase of the disease, reticular pseudodrusen-like lesions appear in the superior perifovea and tend to coalescence horizontally into a flat, continuous, reflective material localized between the retinal pigmented epithelium and Bruch's membrane. Over time, EMAP causes profound RPE and outer retinal atrophy in the macular area, with a recent classification reporting a 3-stages evolution pattern. Blue autofluorescence showed rapidly evolving atrophy with either hyperautofluorescent or isoautofluorescent borders. Significant similarities between the diffuse-trickling phenotype of geographic atrophy and EMAP have been reported. Macular neovascularization is a possible complication.

CONCLUSION

EMAP is specific form of early-onset atrophic macular degeneration with rapid evolution and no treatment. Further studies are needed to assess the best management.

Extent and Topography of Subretinal Drusenoid Deposits Associate With Rod-Mediated Vision in Aging and AMD: ALSTAR2 Baseline

Purpose

In AMD, rod-mediated dark adaptation (RMDA) at 5° eccentricity is slower in eyes with subretinal drusenoid deposits (SDDs) than in eyes without. Here we quantified SDD burden using supervised deep learning for comparison to vision and photoreceptor topography.

Methods

In persons ≥60 years from the Alabama Study on Early Age-Related Macular Degeneration 2, normal, early AMD, and intermediate AMD eyes were classified by the AREDS nine-step system. A convolutional neural network was trained on 55°-wide near-infrared reflectance images for SDD segmentation. Trained graders annotated ground truth (SDD yes/no). Predicted and true datasets agreed (Dice coefficient, 0.92). Inference was manually proofread using optical coherence tomography. The mean SDD area (mm2) was compared among diagnostic groups (linear regression) and to vision (age-adjusted Spearman correlations). Fundus autofluorescence images were used to mask large vessels in SDD maps.

Results

In 428 eyes of 428 persons (normal, 218; early AMD, 120; intermediate AMD, 90), the mean SDD area differed by AMD severity (P < 0.0001): 0.16 ± 0.87 (normal), 2.48 ± 11.23 (early AMD), 11.97 ± 13.33 (intermediate AMD). Greater SDD area was associated with worse RMDA (r = 0.27; P < 0.0001), mesopic (r = -0.13; P = 0.02) and scotopic sensitivity (r = -0.17; P < 0.001). SDD topography peaked at 5° superior, extended beyond the Early Treatment of Diabetic Retinopathy Study grid and optic nerve, then decreased.

Conclusions

SDD area is associated with degraded rod-mediated vision. RMDA 5° (superior retina) probes where SDD is maximal, closer to the foveal center than the rod peak at 3 to 6 mm (10.4°-20.8°) superior and the further eccentric peak of rod:cone ratio. Topographic data imply that factors in addition to rod density influence SDD formation.

Retro Mode Imaging for Detection and Quantification of Sub-RPE Drusen and Subretinal Drusenoid Deposits in Age-Related Macular Degeneration

Background: Drusen and drusenoid deposits are a hallmark of age-related macular degeneration (AMD). Nowadays, a multimodal retinal imaging approach enables the detection of these deposits. However, quantitative data on subretinal drusenoid deposits (SDDs) are still missing. Here, we compare the capability of en-face drusen and SDD area detection in eyes with non-exudative AMD using conventional imaging modalities versus Retro mode imaging. We also quantitatively assess the topographic distribution of drusen and SDDs. Methods: In total, 120 eyes of 90 subjects (mean age ± standard deviation = 74.6 ± 8.6 years) were included. Coherent en-face drusen and SDD areas were measured via near-infrared reflectance, green (G-) and blue (B-) fundus autofluorescence (AF), and Retro mode imaging. Drusen phenotypes were classified by correlating en-face drusen areas using structural high-resolution spectral domain optical coherence tomography. The topographic distribution of drusen was analyzed according to a modified ETDRS (Early Treatment of Diabetic Retinopathy Study) grid. Intraclass correlation coefficient (ICC) analysis was applied to determine the inter-reader agreement in the SDD en-face area assessment. Results: The largest coherent en-face drusen area was found using Retro mode imaging with a mean area of 105.2 ± 45.9 mm2 (deviated left mode (DL)) and 105.4 ± 45.5 mm2 (deviated right mode (DR)). The smallest en-face drusen areas were determined by GAF (50.9 ± 42.6 mm2) and BAF imaging (49.1 ± 42.9 mm2) (p < 0.001). The inter-reader agreement for SDD en-face areas ranged from 0.93 (DR) to 0.70 (BAF). The topographic analysis revealed the highest number of SDDs in the superior peripheral retina, whereas sub-retinal pigment epithelium drusen were mostly found in the perifoveal retina. Retro mode imaging further enabled the detection of the earliest SDD stages. Conclusions: Retro mode imaging allows for a detailed detection of drusen phenotypes. While hundreds/thousands of SDDs can be present in one eye, the impact of SDD number or volume on AMD progression still needs to be evaluated. However, this new imaging modality can add important knowledge on drusen development and the pathophysiology of AMD.

Quantifying cardiac dysfunction and valvular heart disease associated with subretinal drusenoid deposits in age-related macular degeneration

BACKGROUND/AIMS

Demonstrate through objective multidisciplinary imaging that subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are linked to both coexistent valvular heart disease (VHD) and reduced systemic perfusion via cardiac index (CI).

METHODS

Post-hoc analysis of cross-sectional study. 200 intermediate AMD (iAMD) subjects were assigned by masked readers to two groups: SDD (with or without drusen) and drusen (only) based on multimodal ophthalmic imaging. 65 transthoracic echocardiograms (TTEs) reports were available for cardiologist evaluation of VHD severity of the four cardiac valves and the presences of precursor lesions of aortic sclerosis (ASc) and mitral annular calcification (MAC). Necessary parameters to calculate CI were also obtained. Univariate testing was performed using Fisher's Exact test and t-test.

RESULTS

82.6% (19/23) of the iAMD subjects with at least one moderate/severe VHD had concurrent SDDs (p = 0.0040). All cases of aortic regurgitation (6/6, p = 0.0370) and mitral regurgitation (13/13, p = 0.0004) were found with coexisting SDDs. Stenotic VHD was not significantly associated with SDDs, however 70.7% of subjects with ASc (29/41, p = 0.0108) and 76.0% of subjects with MAC (19/25, 0.0377) had coexisting SDDs. CI was available in 48 subjects and was significantly below normal levels in the SDD cohort (mean CI SDD 1.95 ± 0.60 L/min/m2, non-SDD 2.71 ± 0.73 L/min/m2, p = 0.0004).

CONCLUSIONS

Several specific VHDs have been found associated with the SDD form of AMD. Decreased systemic perfusion as measured by CI was also associated with SDDs, which supports a perfusion hypothesis of SDD pathogenesis. Further research is warranted to understand the relationship between cardiovascular disease and SDDs.

Correlation between ellipsoid zone thickness and the presence of subretinal drusenoid deposits in age-related macular degeneration

PURPOSE

Subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are associated with systemic vascular diseases that compromise ocular perfusion. We demonstrate that SDDs are associated with decreased ellipsoid zone (EZ) thickness, further evidence of hypoxic damage.

METHODS

Post hoc analysis of a cross-sectional study. 165 AMD subjects (aged 51-100; 61% women). Spectral-domain optical coherence tomography was obtained in both eyes. Masked readers assigned subjects to three groups: drusen only, SDD+drusen (SDD+D) and SDD only. EZ thickness was measured subfoveally and 2000 µm nasally, temporally, superiorly and inferiorly from the fovea. Univariate testing was performed using two-tailed t-tests with Bonferroni correction.

RESULTS

The mean EZ thickness differences between the SDD+D and drusen-only groups were (in μm) 1.10, 0.67, 1.21, 1.10 and 0.50 at the foveal, nasal, temporal, superior and inferior locations, respectively (p=0.08 inferiorly, otherwise p≤0.01); between the SDD-only and drusen-only groups, the differences were 3.48, 2.48, 2.42, 2.08 and 1.42 (p≤0.0002). Differences in EZ thicknesses across all subjects and between groups were not significantly different based on gender, race or age.

CONCLUSION

Subjects with SDDs (±drusen) had thinner EZs than those with drusen only, and the inferior EZ was least affected. EZs were thinnest in SDD-only subjects. This thinning gradation is consistent with progressive destruction of highly oxygen-sensitive mitochondria in the EZ from hypoxia. These findings support the reduced ophthalmic perfusion hypothesis for the formation of SDDs secondary to high-risk systemic vasculopathy.

Considerations for the Identification and Management of Geographic Atrophy: Recommendations from an Expert Panel

Newly approved treatments for patients with geographic atrophy are changing the treatment paradigm, highlighting the need for eye care providers (ECPs) to have a set of recommendations on how to best manage GA patients. Here, we outline how to identify various stages of age-related macular degeneration including geographic atrophy (GA) by examining optimal management scenarios implicating various ECPs and reviewing treatment considerations for patients with GA. Early identification of GA will lead to optimal patient outcomes, while a standardized management scenario will reduce clinical burden among ECPs treating patients with GA.

Internal Carotid Artery Stenosis and Ipsilateral Subretinal Drusenoid Deposits

Purpose

Subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are strongly associated with vasculopathies such as myocardial infarction and ischemic stroke. This study evaluates ischemic stroke subjects for SDDs to determine whether ocular hypoperfusion from internal carotid artery (ICA) stenosis is associated with ipsilateral SDDs.

Methods

A cross-sectional study at Mount Sinai Hospital recruited 39 subjects with ischemic stroke (aged 52-90; 18 women, 21 men); 28 completed all study procedures. Computed tomography (CT) of the head and neck evaluated 54/56 ICAs for stenosis criteria: none (n = 33), mild (n = 12), moderate (n = 3), severe (n = 3), and complete (n = 3). Spectral-domain optical coherence tomography (SD-OCT) scans were read to consensus by two masked graders for soft drusen, SDDs and choroidal thickness (CTh; choroidal thinning = CTh < 250 µm). Univariate testing was done with Fisher's exact test. Multivariate logistic regression models tested age, gender, and ICA stenosis as covariates.

Results

Moderate or more ICA stenosis (≥50%-69%) was significantly associated with ipsilateral choroidal thinning (P = 0.021) and ipsilateral SDDs (P = 0.005); the latter were present distal to six of nine stenosed ICAs versus five of 33 normal ICAs. Mild ICA stenosis (≥1%-49%) was not significantly associated with ipsilateral SDDs. Multivariate regression found that older age (P = 0.015) and moderate or more ICA stenosis (P = 0.011) remained significant independent risks for ipsilateral SDDs.

Conclusions

At least moderate ICA stenosis (≥50%-69%) is strongly associated with ipsilateral SDDs and choroidal thinning, supporting downstream ophthalmic artery and choroidal hypoperfusion from ICA stenosis as the mechanism for SDD formation. SDDs may thus serve as sensitive biomarkers for ischemic stroke and other vascular diseases.

Prevalence and determinants of subretinal drusenoid deposits in patients' first-degree relatives

PURPOSE

Subretinal drusenoid deposits (SDDs) are distinct extracellular alteration anterior to the retinal pigment epithelium (RPE). Given their commonly uniform phenotype, a hereditary predisposition seems likely. Hence, we aim to investigate prevalence and determinants in patients' first-degree relatives.

METHODS

We recruited SDD outpatients at their visits to our clinic and invited their relatives. We performed a full ophthalmic examination including spectral domain-optical coherence tomography (SD-OCT) and graded presence, disease stage of SDD as well as percentage of infrared (IR) en face area affected by SDD. Moreover, we performed genetic sequencing and calculated a polygenic risk score (PRS) for AMD. We conducted multivariable regression models to assess potential determinants of SDD and associations of SDD with PRS.

RESULTS

We included 195 participants, 123 patients (mean age 81.4 ± 7.2 years) and 72 relatives (mean age 52.2 ± 14.2 years), of which 7 presented SDD, resulting in a prevalence of 9.7%. We found older age to be associated with SDD presence and area in the total cohort and a borderline association of higher body mass index (BMI) with SDD presence in the relatives. Individuals with SDD tended to have a higher PRS, which, however, was not statistically significant in the multivariable regression.

CONCLUSION

Our study indicates a potential hereditary aspect of SDD and confirms the strong association with age. Based on our results, relatives of SDD patients ought to be closely monitored for retinal alterations, particularly at an older age. Further longitudinal studies with larger sample size and older relatives are needed to confirm or refute our findings.

Association between Subretinal Drusenoid Deposits and Age-Related Macular Degeneration in Multimodal Retinal Imaging

Multimodal retinal imaging enables the detection of subretinal drusenoid deposits (SDD) with significantly greater accuracy compared to fundus photography. The study aimed to analyze a relationship between the presence of SDD, the clinical picture of AMD, and disease progression in a 3 year follow-up. A total of 602 eyes of 339 patients with a diagnosis of AMD, of which 121 (55%) had SDD confirmed in multimodal retinal imaging, were enrolled in the study. SDD was related to a more advanced stage of AMD (p = 0.008), especially with the presence of geographic atrophy (OR = 4.11, 95% CI 2.02-8.38, p < 0.001). Eyes with SDD presented significantly lower choroidal and retinal thickness (ATC: 210.5 μm, CRT: 277 μm, respectively) and volume (AVC: 0.17 mm3, CRV: 8.29 mm3, p < 0.001, respectively) compared to SDD-negative eyes (ATC: 203 μm, CRT: 277 μm; AVC: 7.08 mm3, 8.54 mm3, p < 0.001). Accordingly, the prevalence of pachychoroids and pachyvessels was significantly lower in the SDD present group than in eyes without SDD (p = 0.004; p = 0.04, respectively). Neither demographic factors, lipid profile, genetic predisposition, systemic vascular disease comorbidities, nor parameters of retinal vessels were affected by the presence of SDD. We found no effect of SDD presence on AMD progression (p = 0.12). The presence of SDD appeared to be related to local rather than systemic factors.

Epidemiology of geographic atrophy and its precursor features of intermediate age-related macular degeneration

Globally age-related macular degeneration (AMD) is a leading cause of blindness with a significant impact on quality of life. Geographic atrophy (GA) is the atrophic late form of AMD and its prevalence increases markedly with age with around 1 in 5 persons aged 85 and above having GA in at least one eye. Bilateral GA leads to severe visual impairment thus posing a significant burden on patients, careers and health providers. The incidence and prevalence of GA varies across different geographic regions, with the highest rates in those of European ancestry. Although heterogeneity in definitions of GA and reporting strategy can explain some of the discrepancies, the data overall are consistent in showing a lower prevalence in other ethnicities such as those of Asian heritage. This is at present unexplained but thought to be due to the existence of protective factors such as differences in eye pigmentation, diet, environmental exposures and genetic variability. This review covers key aspects of the prevalence and incidence of the ocular precursor features of GA (large drusen, pigmentary abnormalities and reticular pseudo-drusen), the late stage of GA and factors that have been known to be associated with modifying risk including systemic, demographic, environment, genetic and ocular. Understanding the global epidemiology scenario is crucial for the prevention of and management of patients with GA.

Multimodal Imaging of Reticular Pseudodrusen in Turkish Patients

Objectives

To investigate the presence and prevalence of reticular pseudodrusen (RPD) in patients with age-related macular degeneration using multiple imaging modalities and to compare the sensitivity and specificity of these modalities in the detection of RPD.

Materials and Methods

Images from a total of 198 consecutive patients were analyzed prospectively. Color fundus photography, red-free imaging, spectral domain optical coherence tomography (SD-OCT), infrared and blue reflectance (BR) imaging, fundus autofluorescence (FAF), enhanced-depth imaging OCT (EDI-OCT), fundus fluorescein angiography (FFA) and indocyanine green angiography were performed. RPD was diagnosed in the presence of relevant findings in at least two of the imaging methods used.

Results

RPD were detected in 149 eyes (37.6%). In the detection of RPD, color fundus photography, red-free photography, SD-OCT, infrared, FAF, BR, and FFA imaging had sensitivity values of 50%, 57.7%, 91.6%, 95%, 74.6%, 65.7%, and 28.2% and specificity values of 99.6%, 100%, 98.4%, 94.6%, 100%, 99.6%, and 69.8%, respectively.

Conclusion

Infrared imaging had the highest sensitivity. SD-OCT combined with infrared imaging was the most sensitive imaging technique for detecting RPD. The high specificity of FAF, red-free, and BR imaging may be useful to confirm a diagnosis of RPD.

Stages, pathogenesis, clinical management and advancements in therapies of age-related macular degeneration

Age-related macular degeneration (AMD) is a retinal degenerative disorder prevalent in the elderly population, which leads to the loss of central vision. The disease progression can be managed, if not prevented, either by blocking neovascularization ("wet" form of AMD) or by preserving retinal pigment epithelium and photoreceptor cells ("dry" form of AMD). Although current therapeutic modalities are moderately successful in delaying the progression and management of the disease, advances over the past years in regenerative medicine using iPSC, embryonic stem cells, advanced materials (including nanomaterials) and organ bio-printing show great prospects in restoring vision and efficient management of either forms of AMD. This review focuses on the molecular mechanism of the disease, model systems (both cellular and animal) used in studying AMD, the list of various regenerative therapies and the current treatments available. The article also highlights on the recent clinical trials using regenerative therapies and management of the disease.

Two potentially distinct pathways to geographic atrophy in age-related macular degeneration characterized by quantitative fundus autofluorescence

BACKGROUND/AIMS

To demonstrate two distinct pathways to geographic atrophy (GA) that originate from soft drusen/ pigment epithelial detachments (PEDs) and subretinal drusenoid deposits (SDDs), respectively, and are characterized by their final quantitative autofluorescence (qAF) levels.

METHODS

23 eyes of 18 patients with GA underwent spectral-domain optical coherence tomography (SD-OCT) and qAF imaging on the qAF-ready Heidelberg Spectralis. 52 GA Regions-of-interest (ROIs), or clusters of adjacent lesions, were selected, and the ROIs were divided into groups by the dominant iAMD precursors on prior serial tracked SD-OCT scans. Mean qAF values and structural SD-OCT findings of groups were compared.

RESULTS

Group 1 lesions (soft drusen/PED precursors, 18/52) were isolated, with lower mean qAF (35.88 ± 12.75 units); group 3 lesions (SDD precursors, 12/52) were multilobular, with significantly higher mean qAF (71.62 ± 12.12 units, p < 0.05). Group 2 lesions, (mixed precursors, 22/52) had intermediate mean qAF (58.13 ± 67.92 units). Significantly greater prevalence of split RPE/ Bruch's membrane complex in SDD-associated GA, suggesting basal laminar deposit (BLamD), than in drusen-associated lesions was the major structural difference.

CONCLUSION

Quantitative autofluorescence (qAF) of GA lesions may reflect two distinct pathogenic pathways and structural outcomes, originating from soft drusen/PED and subretinal drusenoid deposits (SDDs), with the final qAF values lower or higher, respectively. Basal laminar deposit specifically in and adjacent to SDD-associated lesions may account for their greater autofluorescence. The potential importance of this paradigm is that it could direct, simplify and facilitate research on geographic atrophy by dividing the disease into two components that may be studied separately.

Subretinal drusenoid deposits are strongly associated with coexistent high-risk vascular diseases

Background/aims

Demonstrate that subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are linked to coexistent high-risk vascular diseases (HRVDs).

Methods

Cross-sectional study. Two hundred AMD subjects (aged 51–100 years; 121 women, 79 men) were recruited. Spectral domain optical coherence tomography, autofluorescence and near-infrared reflectance imaging, and lipid profiles were obtained. Subjects were assigned by health history questionnaires into those with or without HRVDs, defined as: cardiac valve defect (eg, aortic stenosis), myocardial defect (eg, myocardial infarction) and stroke/transient ischaemic attack. Masked readers assigned subjects into two groups: SDD (with or without drusen) and drusen (only). Univariate testing was performed by χ2test. We built multivariate regression models to test relationships of coexistent HRVD to SDD status, lipid levels and other covariates.

Results

The prevalence of HRVD was 41.2% (40/97) and 6.8% (7/103) in the SDD and non-SDD groups, respectively (correlation of SDD with HRVD, p=9×10−9, OR 9.62, 95% CI 4.04 to 22.91). Multivariate regressions: only SDDs and high-density lipoprotein (HDL) in the first two HDL quartiles remained significant for HRVD (p=9.8×10−5, 0.021, respectively). Multivariate regression model: SDDs and an HDL in Q1 or Q2 identified the presence of HRVD with the accuracy of 78.5%, 95% CI 72.2% to 84.0%.

Conclusions

High-risk cardiovascular and neurovascular diseases were accurately identified in an AMD cohort from SDDs and HDL levels. The SDDs may be related to inadequate ocular perfusion resulting from the systemic vasculopathies. Further research with this paradigm is warranted and might reduce mortality and morbidity from vascular disease.

Enhanced Detection of Reticular Pseudodrusen on Color Fundus Photos by Image Embossing

PURPOSE

To evaluate whether processing a color fundus photo (CFP) using an image embossing technique can improve the detection of reticular pseudodrusen (RPD).

METHODS

This post-hoc analysis included the eyes of subjects enrolled in the Amish Eye Study with early or intermediate age-related macular degeneration and evidence of RPD. All patients underwent CFP, near-infrared reflectance (NIR), and fundus autofluorescence (FAF) imaging. The ground-truth presence of RPD was established with a combination of NIR and FAF imaging. An embossing processed (EP) image was created by replacing each pixel of the CFP image with a highlight or a shadow representing light and dark boundaries in the original CFP image. The presence of RPD in CFP and EP images was assessed by two graders in a masked fashion and the sensitivity of CFP and EP for detection of RPD was evaluated. Cohen's kappa (k) was used to test inter-grader agreement for CFP and EP.

RESULTS

A total of 106 eyes from 62 patients with RPDs were analyzed. The sensitivity for detection of RPD on CFP and EP was 63.2% (95%CI: 52.0%-74.4%) and 91.5% (95%CI: 85.0%-98.0%), respectively. The inter-rater reliabilities of CFP and EP for RPD detection were 0.81 and 0.84, respectively.

CONCLUSIONS

Embossing of CFP can improve the sensitivity for detection of RPD. The embossing technique can be a useful tool for better assessment of the true frequency of RPD in datasets where only CFP images are available.

Reticular Pseudodrusen Are Associated With More Advanced Para-Central Photoreceptor Degeneration in Intermediate Age-Related Macular Degeneration

Purpose

The purpose of this study was to examine retinal topographical differences between intermediate age-related macular degeneration (iAMD) with reticular pseudodrusen (RPD) versus iAMD without RPD, using high-density optical coherence tomography (OCT) cluster analysis.

Methods

Single eyes from 153 individuals (51 with iAMD+RPD, 51 with iAMD, and 51 healthy) were propensity-score matched by age, sex, and refraction. High-density OCT grid-wise (60 × 60 grids, each approximately 0.01 mm2 area) thicknesses were custom-extracted from macular cube scans, then compared between iAMD+RPD and iAMD eyes with correction for confounding factors. These "differences (µm)" were clustered and results de-convoluted to reveal mean difference (95% confidence interval [CI]) and topography of the inner retina (retinal nerve fiber, ganglion cell, inner plexiform, and inner nuclear layers) and outer retina (outer plexiform/Henle's fiber/outer nuclear layers, inner and outer segments, and retinal pigment epithelium-to-Bruch's membrane [RPE-BM]). Differences were also converted to Z-scores using normal data.

Results

In iAMD+RPD compared to iAMD eyes, the inner retina was thicker (up to +5.89 [95% CI = +2.44 to +9.35] µm, P < 0.0001 to 0.05), the outer para-central retina was thinner (up to -3.21 [95% CI = -5.39 to -1.03] µm, P < 0.01 to 0.001), and the RPE-BM was thicker (+3.38 [95% CI = +1.05 to +5.71] µm, P < 0.05). The majority of effect sizes (Z-scores) were large (-3.13 to +1.91).

Conclusions

OCT retinal topography differed across all retinal layers between iAMD eyes with versus without RPD. Greater para-central photoreceptor thinning in RPD eyes was suggestive of more advanced degeneration, whereas the significance of inner retinal thickening was unclear. In the future, quantitative evaluation of photoreceptor thicknesses may help clinicians monitor the potential deleterious effects of RPD on retinal integrity.

Subretinal Drusenoid Deposits and Lower Serum High-Density Lipoprotein Cholesterol Levels Possess Latent Relation to Cardiovascular Disease and Can Be a Feasible Predictor

Objective

To ascertain whether lipid-related subretinal drusenoid deposits (SDD) are correlated with coexisting cardiovascular disease (CVD), as well as to reveal latent serum markers of CVD.

Methods

Patients older than 50 years and plagued by age-related macular degeneration (AMD) were included. Subjects with other retinal degenerations and vascular diseases, any recent treatment at other medical care institutions, and any previous oculopathy or ophthalmic surgery were excluded. All subjects were examined to ascertain whether they possess SDD, to analyze serum cholesterols, including low-density lipoprotein cholesterol (LDL), triglycerides (TG), high-density lipoprotein cholesterol (HDL), and total cholesterol (TC). Subjects were divided into SDD and non-SDD groups and further divided into subgroups by assessment of pump defect, valve defect, and carotid defect. Finally, logistic model trees and random forest algorithm analysis were performed.

Results

A total of 85 AMD patients including 43 with and 42 without SDD were involved. The 42 AMD (97.67%, 42/43) patients with SDD showed CVD, including 3 subjects presenting valve defect, 3 subjects presenting carotid defect, 8 subjects presenting pump defect, 14 subjects presenting both pump and valve defects, and 14 subjects presenting pump, valve, and carotid defects. By contrast, 5 AMD (11.90%, 5/42) patients without SDD showed CVD. Cholesterol level of SDD subjects presented significant higher TC (5.66 ± 1.01 vs. 5.58 ± 0.72, p = 0.032, Wilcoxon test) and lower HDL cholesterol (61 ± 17 vs. 70 ± 21, p = 0.031, Wilcoxon test) than that of non-SDD. The cases with HDL < 62 mg/dL were significantly related to CVD (p = 0.013, Wilcoxon test), and the cases with HDL < 40 mg/dL were not (p = 0.659, Wilcoxon test). Through machine learning based on the image from color fundus photography, the accuracy of predicting CVD was 95%.

Conclusions

The presence of SDD of AMD and lower serum HDL cholesterol level can predict certain CVD for AMD patients. The machine learning based on the SDD image and serum HDL cholesterol may open new avenue for the detection of CVD as a noninvasive approach.

Reticular Pseudodrusen on the Risk of Progression in Intermediate Age-Related Macular Degeneration

PURPOSE

To examine the association between reticular pseudodrusen (RPD) and progression to late age-related macular degeneration (AMD) in individuals with intermediate AMD.

DESIGN

Prospective cohort study.

METHODS

Two hundred eighty eyes from 140 participants with bilateral large drusen underwent multimodal imaging (MMI), including optical coherence tomography (OCT), near-infrared reflectance (NIR), fundus autofluorescence, and color fundus photography (CFP), at 6-monthly intervals up over a 36-month follow-up period. The presence of RPD per eye was determined based on either a combined MMI criterion, or each individual imaging modality, and their extent measured on combined OCT and NIR imaging. The association between the presence of RPD on different imaging modalities, and their extent, with the development of late AMD (including OCT-defined atrophy) was evaluated.

RESULTS

The presence of RPD on MMI, or any of its individual modalities, at baseline was not significantly associated with an increased rate of developing late AMD, with or without adjusting for risk factors for AMD progression (age, drusen volume on OCT, and pigmentary abnormalities on CFP; all P ≥ 0.205). The extent of RPD present was also not significantly associated with an increased rate of developing late AMD, with or without adjustment for risk factors for AMD progression (both P ≥ 0.522).

CONCLUSIONS

In this cohort with bilateral large drusen, the presence of RPD was not significantly associated with an increased risk of developing late AMD. Additional longitudinal studies in all stages of AMD are needed to understand the implications of RPD on vision loss in this condition.

Prevalence and determinants of reticular pseudodrusen in the Russian Ural Eye and Medical Study

PURPOSE

To assess the prevalence of reticular pseudodrusen (RPD) and their determinants.

METHODS

The Population-based Ural Eye and Medical Study conducted in Bashkortostan/Russia included 5899 participants aged 40+ years. Presence of RPDs was assessed on conventional colour fundus photographs, red-free fundus images and optical coherence tomographic images.

RESULTS

The study included 4914 (83.3%) individuals (mean age: 58.5 ± 10.5 years; range: 40-94 years). Using two age limits (>55 years and 40+ years) for the definitions of RPD and AMD (age-related macular degeneration), RPD prevalence was 186/4914 (3.8%; 95% confidence interval (CI): 3.3, 4.3) and 246/4914 (5.0%, 95% CI: 4.4, 5.6), respectively, and the prevalence of any AMD without RPD was 182/4914 (3.7%: 95% CI: 3.2, 4.2) and 224/4914 (4.6%; 95% CI: 4.0, 5.1) respectively. Within the subgroup of early AMD, intermediate AMD and late AMD, RPD prevalence (age limit: 40+ years) was 55.1% (95% CI: 49.5, 60.8), 42.9% (95% CI: 33.8, 51.9) and 33.3% (95% CI: 16.4, 50.3) respectively. In multivariable analysis, higher RPD prevalence (age limit 40+ years) was associated with higher age (odds ratio (OR): 1.08; 95% CI: 1.07, 1.10; p < 0.001), rural region of habitation (OR: 3.81; 95% CI: 2.76, 5.24; p < 0.001) and lower percentage of lymphocytes on leukocyte counts (OR: 0.95; 95% CI: 0.93, 0.97; p < 0.001). Higher prevalence of any AMD without RPD was associated with urban region (OR: 1.58; 95% CI: 1.18, 2.11; p = 0.002), lower diabetes prevalence (OR: 0.55; 95% CI: 0.33, 0.90; p = 0.02) and shorter axial length (OR: 0.85; 95% CI: 0.74, 0.98; p = 0.03), after adjusting for age.

CONCLUSIONS

Reticular pseudodrusen (mean prevalence: 3.8% (age limit >55 years); 5.0% (age limit 40+ years)) differs from AMD without RPD in its association with urban region (AMD without RPD: rural region), lower lymphocyte percentage (AMD without RPD: no association) and a lack of associations with axial length (AMD without RPD: shorter axial length) and with diabetes prevalence (AMD without RPD: lower diabetes prevalence).

Gender as an effect modifier in the relationship between hypertension and reticular pseudodrusen in patients with early or intermediate age-related macular degeneration

AIM

To determine whether the prevalence of treated hypertension is higher among males or females with early/intermediate (e/i) age-related macular degeneration (AMD) with and without bilateral reticular pseudodrusen (RPD).

METHODS

Retrospective review of the records of patients with e/iAMD who were recruited into the University of Colorado AMD registry between July 2014 and November 2019. Images were classified using the Beckman Initiative criteria and presence/absence of RPD. Patients were categorized into three groups: 1) e/iAMD with RPD; 2) e/iAMD without RPD; 3) control patients who did not have AMD. Multinomial logistic regression analysis was used for adjusted analysis with odds ratios (OR) and confidence intervals (CI).

RESULTS

There were 260 patients with e/iAMD of which 101 had bilateral RPD and 159 had no RPD, and 221 controls. Overall, 62% of patients were female and the three groups did not differ by gender. When stratified by gender, the female e/iAMD/RPD group had a higher prevalence of hypertension, 64.1% vs 45.2% for controls, OR=2.2 (95%CI: 1.2-4.0). The frequency of hypertension in the e/iAMD/no RPD group was 54.1% and did not significantly differ from the control group. Among males, prevalence rates of treated hypertension did not differ. There is a significant interaction of hypertension and gender for the e/iAMD/RPD group such that women with e/iAMD who had RPD were significantly more likely to have hypertension (P=0.042). This relationship was not significant in the e/iAMD/no RPD group (P=0.269).

CONCLUSION

Among females treated hypertension is significantly higher among e/iAMD/RPD patients, whereas for males there is no significant association.

Subretinal Drusenoid Deposit Formation: Insights From Turing Patterns

Purpose

The purpose of this study was to demonstrate that the organized formation of subretinal drusenoid deposits (SDDs) may be a Turing pattern.

Methods

A Java-based computational model of an inferred reaction-diffusion system using paired partial differential equations was used to create topographic images. Reaction kinetics were varied to illustrate a spectrum of pattern development, which were then compared to dot-like, reticular, and confluent SDD patterns observed clinically.

Results

A reaction-diffusion system using two agents, one an “activator” that increases its own production, and the other an “inhibitor” that decreases the activator's production, can create patterns that match the spectrum of topographic appearance of organized SDD. By varying a single parameter, the strength of the activator, the full spectrum of clinically observed SDD patterns can be generated. A new pattern, confluence with holes, is predicted and identified in one case example.

Conclusions

The formation of clinically significant SDD and its different patterns can be explained using Turing patterns obtained by simulating a two-component reaction-diffusion system.

Translational Relevance

This model may be able to guide future risk stratification for patients with SDD, and provide mechanistic insights into the cause of the disease.

Subretinal Drusenoid Deposits and Soft Drusen: Are They Markers for Distinct Retinal Diseases?

PURPOSE

Soft drusen and subretinal drusenoid deposits (SDDs) characterize two pathways to advanced age-related macular degeneration (AMD), with distinct genetic risks, serum risks and associated systemic diseases.

METHODS

126 Subjects with AMD were classified as SDD (with or without soft drusen), or non-SDD (drusen only) by retinal imaging, with serum risks, genetic testing, and histories of cardiovascular disease (CVD) and stroke.

RESULTS

There were 62 SDD subjects and 64 non-SDD subjects, 51 total had CVD or stroke.SDD correlated significantly with: lower mean serum HDL (61±18 vs. 69±22 mg/dl, p= 0.038, t test); CVD and stroke (34/51 SDD, p= 0.001, chi square); ARMS2 risk allele (p= 0.019, chi square), but not with CFH risk allele (p = 0.66). Non-SDD (drusen only) correlated/trended with: APOE2 (p= 0.032) and CETP (p= 0.072) risk alleles (chi square). Multivariate independent risks for SDD were: CVD and stroke (p= 0.008), and ARMS2 homozygous risk (p= 0.038).

CONCLUSION

SDD and non-SDD subjects have distinct systemic associations, serum and genetic risks. SDD are associated with CVD and stroke, ARMS2 risk, and lower HDL; non-SDD with higher HDL, CFH risk and two lipid risk genes. These and other distinct associations suggest these lesions are markers for distinct diseases.

Subretinal drusenoid deposits: An update

A wide spectrum of phenotypic manifestations characterizes age-related macular degeneration (AMD). Drusen is considered the hallmark of AMD and is located underneath the retinal pigment epithelium (RPE). In contrast, subretinal drusenoid deposits (SDDs), also known as reticular pseudodrusens, are located in the subretinal space, on top of the RPE. SDDs are poorly detected by clinical examination and color fundus photography. Multimodal imaging is required for their proper diagnosis. SDDs are topographically and functionally related to rods. SDDs cause a deep impairment in retinal sensitivity and dark adaptation. SDDs are dynamic structures that may grow, fuse with each other, or regress over time. An intermediate step in some eyes is the development of an acquired vitelliform lesion. The presence of SDD confers an eye a high risk for the development of late AMD. SDD leads to macular neovascularization, particularly type 3, geographic atrophy, and outer retinal atrophy.

Genetic and environmental risk factors for reticular pseudodrusen in the EUGENDA study

PURPOSE

The purpose of this study was to analyze genetic and nongenetic associations with reticular pseudodrusen (RPD) in patients with and without age-related macular degeneration (AMD).

METHODS

This case-control study included 2,719 consecutive subjects from the prospective multicenter European Genetic Database (EUGENDA). Color fundus photographs and optical coherence tomography (OCT) scans were evaluated for the presence of AMD and RPD. Association of RPD with 39 known AMD polymorphisms and various nongenetic risk factors was evaluated. Stepwise backward variable selection via generalized linear models (GLMs) was performed based on models including the following: a) age, sex, and genetic factors and b) all predictors. Receiver operating characteristic (ROC) curves and the areas under the curve (AUCs) were determined.

RESULTS

RPD were present in 262 cases (no AMD, n = 9 [0.7%; early/intermediate AMD, n = 75 [12.4%]; late AMD, n = 178 [23.8%]). ROC analysis of the genetic model including age, APOE rs2075650, ARMS2 rs10490924, CFH rs800292, CFH rs12144939, CFI rs10033900, COL8A1 rs13081855, COL10A1 rs3812111, GLI3 rs2049622, and SKIV2L rs4296082 revealed an AUC of 0.871. Considering all possible predictors, backward selection revealed a slightly different set of genetic factors, as well as the following nongenetic risk factors: smoking, rheumatoid arthritis, steroids, antiglaucomatous drugs, and past sunlight exposure; the results showed an AUC of 0.886.

CONCLUSIONS

RPD share a variety of genetic and nongenetic risk factors with AMD. Future AMD grading systems should integrate RPD as an important risk phenotype.

Role of Optical Coherence Tomography Imaging in Predicting Progression of Age-Related Macular Disease: A Survey

In developed countries, age-related macular degeneration (AMD), a retinal disease, is the main cause of vision loss in the elderly. Optical Coherence Tomography (OCT) is currently the gold standard for assessing individuals for initial AMD diagnosis. In this paper, we look at how OCT imaging can be used to diagnose AMD. Our main aim is to examine and compare automated computer-aided diagnostic (CAD) systems for diagnosing and grading of AMD. We provide a brief summary, outlining the main aspects of performance assessment and providing a basis for current research in AMD diagnosis. As a result, the only viable alternative is to prevent AMD and stop both this devastating eye condition and unwanted visual impairment. On the other hand, the grading of AMD is very important in order to detect early AMD and prevent patients from reaching advanced AMD disease. In light of this, we explore the remaining issues with automated systems for AMD detection based on OCT imaging, as well as potential directions for diagnosis and monitoring systems based on OCT imaging and telemedicine applications.

Population-Based Prevalence and 5-Year Change of Soft Drusen, Pseudodrusen, and Pachydrusen in a Japanese Population

Purpose

To elucidate the prevalence of soft drusen, pseudodrusen, and pachydrusen and their 5-year changes in a Japanese population.

Design

Longitudinal population-based cohort study conducted from 2013 through 2017.

Participants

Residents 40 years of age or older.

Methods

Nonmydriatic color fundus photographs were used to grade drusen subtypes and retinal pigment epithelium (RPE) abnormalities according to the Three Continent Age-Related Macular Degeneration Consortium. The 5-year changes of each drusen were investigated.

Main Outcome Measures

The prevalence of each drusen subtype and the 5-year changes of each drusen.

Results

Among 1731 participants, 1660 participants had gradable photographs that were assessed. The age-adjusted prevalence of soft drusen, pachydrusen, and pseudodrusen was 4.3% (95% confidence interval [CI], 3.2%–5.8%), 7.7% (95% CI, 6.2%–9.7%), and 2.8% (95% CI, 1.7%–4.2%), respectively. Pachydrusen accounted for 82.0% (n = 50) of the extramacular drusen (n = 61). Pigment abnormalities were seen in 28.3% and 8.3% of eyes with soft drusen and pachydrusen, respectively (P < 0.0001). Longitudinal changes were investigated in 1444 participants with follow-up examinations, which showed an increase in size in 8.3% and 3.7% and regression in 1.7% and 5.5% for eyes with soft drusen and pachydrusen, respectively. No participants demonstrated RPE atrophy after pachydrusen regression.

Conclusions

The prevalence of pachydrusen was higher than that of soft drusen and pseudodrusen combined. Pachydrusen may regress over time and typically is not associated with RPE atrophy as detected using color fundus photographs.

Reticular pseudodrusen: A critical phenotype in age-related macular degeneration

Reticular pseudodrusen (RPD), or subretinal drusenoid deposits (SDD), refer to distinct lesions that occur in the subretinal space. Over the past three decades, their presence in association with age-related macular degeneration (AMD) has become increasingly recognized, especially as RPD have become more easily distinguished with newer clinical imaging modalities. There is also an increasing appreciation that RPD appear to be a critical AMD phenotype, where understanding their pathogenesis will provide further insights into the processes driving vision loss in AMD. However, key barriers to understanding the current evidence related to the independent impact of RPD include the heterogeneity in defining their presence, and failure to account for the confounding impact of the concurrent presence and severity of AMD pathology. This review thus critically discusses the current evidence on the prevalence and clinical significance of RPD and proposes a clinical imaging definition of RPD that will help move the field forward in gathering further key knowledge about this critical phenotype. It also proposes a putative mechanism for RPD formation and how they may drive progression to vision loss in AMD, through examining current evidence and presenting novel findings from preclinical and clinical studies.

Reticular Pseudodrusen Characteristics and Associations in the Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2), an Ancillary Study of the Women's Health Initiative

PURPOSE

To determine the prevalence and morphologic features of reticular pseudodrusen (RPD) and their association with participant demographics and age-related macular degeneration (AMD) status in the Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2) sample, an ancillary study of the Women's Health Initiative Observational Study.

DESIGN

Cross-sectional, multicenter, natural history study.

PARTICIPANTS

Nine hundred and twenty-seven eyes from 466 postmenopausal women 69 to 101 years of age.

METHODS

Multimodal imaging, including spectral-domain (SD) OCT and infrared reflectance (IR), were used to identify RPD characteristics, including location (within or outside the 6-mm diameter circle centered at the macula), presence of peripapillary RPD, pattern of RPD, and RPD area. Age-related macular degeneration features from SD OCT, IR, and color photographs also were assessed and AMD severity was categorized.

MAIN OUTCOME MEASURES

Reticular pseudodrusen prevalence using SD OCT and IR imaging and AMD status.

RESULTS

Reticular pseudodrusen were present in 130 eyes (14% of eyes, 16% of participants), with increasing prevalence with age: 7% in those younger than 78 years, 14% in those 78 to 83 years of age, and 30% in those older than 83 years. Using clinical classification of AMD with color photography, RPD were seen in 2.4% of eyes with no AMD or aging changes, 11.5% in early AMD, 25.1% in intermediate AMD, and 51.1% in late AMD. Mean RPD area was 17.4 mm2 (standard deviation, 14.7 mm2). Ribbon morphologic RPD (53%) was more common than dot morphologic RPD (36%). Reticular pseudodrusen mostly were located both within and outside the 6-mm circle with primarily superior retinal distribution. Reticular pseudodrusen were visualized with corresponding color fundus photography in only 38 eyes (4% of total eyes). Participants with and without RPD had a visual acuity±standard error of 77.9 ± 1.4 letters and 81.3 ± 0.4 letters, respectively (P = 0.02).

CONCLUSIONS

The prevalence of RPD in CAREDS2 increased with age and was associated with AMD severity. Reticular pseudodrusen were detected in eyes without other features of AMD and could represent an earlier disease state. Multimodal imaging with SD OCT and IR has significantly greater sensitivity for visualizing RPD than color fundus photography.

Fundus Autofluorescence and Clinical Applications

Fundus autofluorescence (FAF) has allowed in vivo mapping of retinal metabolic derangements and structural changes not possible with conventional color imaging. Incident light is absorbed by molecules in the fundus, which are excited and in turn emit photons of specific wavelengths that are captured and processed by a sensor to create a metabolic map of the fundus. Studies on the growing number of FAF platforms has shown each may be suited to certain clinical scenarios. Scanning laser ophthalmoscopes, fundus cameras, and modifications of these each have benefits and drawbacks that must be considered before and after imaging to properly interpret the images. Emerging clinical evidence has demonstrated the usefulness of FAF in diagnosis and management of an increasing number of chorioretinal conditions, such as age-related macular degeneration, central serous chorioretinopathy, retinal drug toxicities, and inherited retinal degenerations such as retinitis pigmentosa and Stargardt disease. This article reviews commercial imaging platforms, imaging techniques, and clinical applications of FAF.

KRT8 (keratin 8) attenuates necrotic cell death by facilitating mitochondrial fission-mediated mitophagy through interaction with PLEC (plectin)

Dysregulation of mitochondrial homeostasis and accumulation of damaged mitochondria cause degenerative diseases such as age-related macular degeneration (AMD). We studied the effects of the intermediate cytofilament KRT8 (keratin 8) on mitochondrial homeostasis in relation to the morphology and function of mitochondria in retinal pigment epithelial cells under oxidative stress. When the mitochondria were damaged owing to oxidative stress, the damaged mitochondria were readily disposed of via mitophagy following mitochondrial fission. During this process, KRT8 was found to physically interact with the mitochondria through PLEC (plectin) and facilitate the mitochondrial fission-mediated mitophagy. However, the association between PLEC-anchoring mitochondria and KRT8 was dwindled by KRT8 phosphorylation under oxidative stress. The efficient KRT8-facilitated mitophagy flux suppressed the accumulation of damaged mitochondria and consequently diminished necrotic cell death under oxidative stress. Thus, by facilitating mitophagy, KRT8 protects RPE cells against necrotic cell death due to oxidative stress.

Incidence and Risk Factors of Reticular Pseudodrusen Using Multimodal Imaging

Importance

Although retinal multimodal imaging is needed for diagnosing reticular pseudodrusen (RPD), the incidence of RPD in the general population typically has been assessed only using fundus photographs, which may underestimate their incidence.

Objectives

To describe the incidence of RPD using retinal color photographs, spectral-domain optical coherence tomography scans, fundus autofluorescence, and near-infrared reflectance images among individuals 77 years of age or older and to analyze the associated risk factors of RPD.

Design, Setting, and Participants

The ALIENOR (Antioxydants, Lipides Essentiels, Nutrition et Maladies Oculaires) Study is a cohort of French individuals 77 years of age or older. Data for this study were collected between February 22, 2011, and February 15, 2017, with a mean (SD) follow-up of 3.7 (1.0) years (range, 1.2-5.6 years). At baseline, 501 individuals were eligible to participate. Of 1002 eyes, 197 had prevalent RPD, advanced age-related macular degeneration, or ungradable images. Of the remaining 805 eyes, 333 were missing follow-up data; therefore, the statistical analyses included data from 472 eyes. Data management and statistical analyses were performed between March 15, 2017, and April 5, 2019.

Main Outcomes and Measures

Reticular pseudodrusen were considered as present if detected by at least 2 of the following imaging methods: color fundus photographs, fundus autofluorescence, near-infrared reflectance, and spectral-domain optical coherence tomography images.

Results

Of the 472 eyes analyzed, 263 (55.7%) were from female participants, and the mean (SD) age was 81.9 (3.2) years. Forty-three eyes developed RPD, corresponding to an annual incidence rate of 2.9% (95% CI, 1.9%-4.4%) per participant and an estimated 5-year risk of 13.5%. In multivariable analysis, 4 risk factors of incident RPD were identified: subfoveal choroidal thinning (hazard ratio [HR], 0.99; 95% CI, 0.99-1.00 per 10-μm decrease in thickness; P = .02) and the presence of the minor allelic variants rs10490924 for ARMS2 (HR, 3.57; 95% CI, 1.80-7.10; P < .001), rs1061170 for CFH (HR, 2.12; 95% CI, 1.02-4.41; P = .04), and rs10468017 for LIPC (HR, 2.57; 95% CI, 1.37-4.82; P = .003). Lipophilic statin therapy was associated with a lower incidence of RPD (HR, 0.13; 95% CI, 0.02-0.74; P = .02).

Conclusions and Relevance

With the use of multimodal imaging, the RPD incidence rate was higher than previously reported in other population-based studies using fundus color images. Individuals with subfoveal choroidal thinning or carrying minor allelic variants for ARMS2, CFH, or LIPC had an increased risk for RPD, whereas lipophilic statin therapy was associated with a lower incidence.

Local Anatomic Precursors to New-Onset Geographic Atrophy in Age-Related Macular Degeneration as Defined on OCT

PURPOSE

In macula-wide analyses, spectral-domain (SD) optical coherence tomography (OCT) features including drusen volume, hyperreflective foci, and OCT-reflective drusen substructures independently predict geographic atrophy (GA) onset secondary to age-related macular degeneration (AMD). We sought to identify SD OCT features in the location of new GA before its onset.

DESIGN

Retrospective study.

PARTICIPANTS

Age-Related Eye Disease Study 2 Ancillary SD OCT Study participants.

METHODS

We analyzed longitudinally captured SD OCT images and color photographs from 488 eyes of 488 participants with intermediate AMD at baseline. Sixty-two eyes with sufficient image quality demonstrated new-onset GA on color photographs during study years 2 through 7. The area of new-onset GA and one size-matched control region in the same eye were segmented separately, and corresponding spatial volumes on registered SD OCT images at the GA incident year and at 2, 3, and 4 years previously were defined. Differences in SD OCT features between paired precursor regions were evaluated through matched-pairs analyses.

MAIN OUTCOME MEASURES

Localized SD OCT features 2 years before GA onset.

RESULTS

Compared with paired control regions, GA precursor regions at 2, 3, and 4 years before (n = 54, 33, and 25, respectively) showed greater drusen volume (P = 0.01, P = 0.003, and P = 0.003, respectively). At 2 and 3 years before GA onset, they were associated with the presence of hypertransmission (P < 0.001 and P = 0.03, respectively), hyperreflective foci (P < 0.001 and P = 0.045, respectively), OCT-reflective drusen substructures (P = 0.004 and P = 0.03, respectively), and loss or disruption of the photoreceptor zone, ellipsoid zone, and retinal pigment epithelium (RPE, P < 0.001 and P = 0.005-0.045, respectively). At 4 years before GA onset, precursor regions were associated with photoreceptor zone thinning (P = 0.007) and interdigitation zone loss (P = 0.045).

CONCLUSIONS

Evolution to GA is heralded by early local photoreceptor changes and drusen accumulation, detectable 4 years before GA onset. These precede other anatomic heralds such as RPE changes and drusen substructure emergence detectable 1 to 2 years before GA. This study thus identified earlier end points for GA as potential therapeutic targets in clinical trials.

Small-Molecule Modulation of PPARs for the Treatment of Prevalent Vascular Retinal Diseases

Vascular-related retinal diseases dramatically impact quality of life and create a substantial burden on the healthcare system. Age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity are leading causes of irreversible blindness. In recent years, the scientific community has made great progress in understanding the pathology of these diseases and recent discoveries have identified promising new treatment strategies. Specifically, compelling biochemical and clinical evidence is arising that small-molecule modulation of peroxisome proliferator-activated receptors (PPARs) represents a promising approach to simultaneously address many of the pathological drivers of these vascular-related retinal diseases. This has excited academic and pharmaceutical researchers towards developing new and potent PPAR ligands. This review highlights recent developments in PPAR ligand discovery and discusses the downstream effects of targeting PPARs as a therapeutic approach to treating retinal vascular diseases.

Association of Drusen Phenotype in Age-Related Macular Degeneration from Human Eye-Bank Eyes to Disease Stage and Cause of Death

PURPOSE

To stage maculopathy, assess and quantify drusen, determine drusen subtype frequency, and compare subtypes with age-related macular degeneration (AMD) stage and cause of death using an eye-bank model of AMD.

DESIGN

Cross-sectional study.

PARTICIPANTS

Two thousand ninety-two human eyes from 1067 eye-bank donors, selected from a population at risk for AMD.

METHODS

We analyzed donor eye tissue images (2005-2020) using both the 4- and 9-step Minnesota Grading System (MGS), an AMD grading system for eye-bank eyes corresponding to the Age-Related Eye Disease Study classification. The 9-step MGS quantifies total drusen area, hyperpigmentation, and depigmentation. We analyzed reticular pseudodrusen (RPD), basal laminar drusen (BLD), and calcified drusen (CaD) frequency within this population and explored associations with AMD stage, donor age, gender, and cause of death. Statistical analyses were performed using Wilcoxon rank-sum and chi-square tests. Testing encompassed staging eye-bank eyes using MGS analysis.

MAIN OUTCOME MEASURES

Drusen subtype frequency associations with AMD stage and cause of death.

RESULTS

We detected RPD in 228 (13%), BLD in 131 (7%), and CaD in 84 (5%) of the examined eyes (n = 1777). All subtypes were associated with advanced AMD (RPD: odds ratio [OR], 3.4 [95% confidence interval (CI), 2.5-4.5; P < 0.0001]; BLD: OR, 2.2 [95% CI, 1.5-3.2; P < 0.0001]; and CaD: OR, 39.1 [95% CI, 16.8-91.0; P < 0.0001]). Only the RPD subtype was associated statistically with cardiovascular death when compared with those without cardiovascular death (48% vs. 32%; OR, 2.0 [95% CI, 1.4-2.9]; P = 0.0002).

CONCLUSIONS

In a large group of eye-bank eyes selected from a population at risk for AMD and graded using the 4-step and 9-step MGS, RPD, BLD, and especially CaD were associated strongly with advanced AMD. The RPD subtype was associated with a cardiovascular cause of death and may represent an ophthalmologic biomarker for cardiovascular disease.

Drusen and pachydrusen: the definition, pathogenesis, and clinical significance

The pachychoroid disease spectrum encompasses seven major retinal conditions including central serous chorioretinopathy (CSC), polypoidal choroidal vasculopathy (PCV), and pachychoroid neovasculopathy or type I macular neovascularisation (MNV) secondary to chronic persistent thickening and dysfunction of the choroidal vasculature. Drusen are focal yellow-white deposits of extracellular debris, which consist of complement proteins, esterified and nonesterified cholesterol, apolipoproteins, carbohydrates, and trace elements, above the retinal pigment epithelium (RPE) or between the RPE and Bruch's membrane. Although drusen are an essential disease precursor of advanced age-related macular degeneration (AMD), a new entity "pachydrusen" has been identified to be associated with some of the enitites that constitute the pachychoroid spectrum. It remains to be determined what the exact differences are between soft drusen, pseudodrusen, and pachydrusen in terms of phenotype, genotype, and pathogenesis. Improving our knowledge in these areas will inevitably improve our understanding of their clinical significance especially as in disease prediction in AMD and the pachychroid spectrum disorders. It remains controversial whether PCV is a subtype of AMD. Understanding the pathogenesis of different types of drusen may also help in addressing if phenotype and/or genotype of type 1 MNV associated with pachychoroid are similar to type 1 MNV related to AMD. Furthermore, because pachydrusen links two pachychoroid diseases, CSC and PCV, it is also of great interest to investigate if CSC is an early stage or a predictor of PCV in future research. In this review, we share our experience in clinical practice and the latest published evidence-based literature to emphasize the differences and similarities in morphology, pathogenesis, and clinical significance of drusen and pachydrusen, a new member of the pachychoroid spectrum disorders.

The role of optical coherence tomography angiography in reticular pseudodrusen

BACKGROUND

To investigate the changes in retinal and choriocapillaris vessel density (VD) in patients effected by early age-related macular degeneration (AMD) and reticular pseudodrusen (RPD), using Optical Coherence Tomography Angiography (OCTA).

METHODS

A total of seventy-eight eyes of 78 patients (43 male, 35 female, mean age 72.61 ± 5.15) with non-neovascular AMD (38 eyes with early AMD and 40 eyes with RPD) was recruited in this observational prospective study. Forty eyes of 40 healthy subjects represented the control group. The VD was measured in superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris in different macular regions.

RESULTS

There were no significant differences in VD of the SCP and DCP among the controls and the two study groups (p > 0.05). The VD of the choriocapillaris revealed a statistically significant reduction in early AMD and RPD groups respect to controls (p < 0.001). Furthermore, the patients with RPD showed a significantly decreased VD respect to patients with early AMD in different macular regions (p < 0.001).

CONCLUSIONS

The quantitative analysis of retinal and choriocapillaris blood flow by OCTA provided useful information regarding the vascular changes in non-neovascular AMD patients suggesting that the choriocapillaris loss is mainly involved in the pathogenesis of RPD.

Revisiting the role of factor H in age-related macular degeneration: Insights from complement-mediated renal disease and rare genetic variants

Ophthalmologists are long familiar with the eye showing signs of systemic disease, but the association between age-related macular degeneration and abnormal complement activation, common to several renal disorders, has only recently been elucidated. Although complement activation products were identified in drusen almost three decades ago, it was not until the early 21st century that a single-nucleotide polymorphism in the complement factor H gene was identified as a major heritable determinant of age-related macular degeneration, galvanizing global efforts to unravel the pathogenesis of this common disease. Advances in proteomic analyses and familial aggregation studies have revealed distinctive clinical phenotypes segregated by the functional effects of common and rare genetic variants on the mature protein and its splice variant, factor H-like protein 1. The predominance of loss-of-function, N-terminal mutations implicate age-related macular degeneration as a disease of general complement dysregulation, offering several therapeutic avenues for its modulation. Here, we explore the molecular impact of these mutations/polymorphisms on the ability of variant factor H/factor H-like protein 1 to localize to polyanions, pentraxins, proinflammatory triggers, and cell surfaces across ocular and renal tissues and exert its multimodal regulatory functions and their clinical implications. Finally, we critically evaluate key therapeutic and diagnostic efforts in this rapidly evolving field.

Subretinal Deposits in Pre-eclampsia and Malignant Hypertension: Implications for Age-Related Macular Degeneration

PURPOSE

To describe the incidence of subretinal deposits that are similar in structure and stage on OCT imaging to subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) in patients with hypertensive choroidopathy secondary to severe pre-eclampsia and malignant hypertension (MHT) and the implications of this ischemic choroidopathy for the pathophysiologic characteristics of SDDs in AMD.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Thirty-three pre-eclampsia patients and 25 MHT patients with serous retinal detachment (SRD) in at least 1 eye were included.

METHODS

Serial multimodal images, including enhanced depth imaging spectral-domain OCT of eyes with hypertensive choroidopathy secondary to pre-eclampsia and MHT, were reviewed at 2 time points, the acute phase (within 4 weeks of initial hypertensive insult) and the recovery phase (beyond 4 weeks).

MAIN OUTCOME MEASURES

Incidence of SDD-like lesions in patients with hypertensive choroidopathy secondary to pre-eclampsia and MHT.

RESULTS

Subretinal drusenoid deposit-like lesions were observed exclusively in eyes with SRD. Serous retinal detachment occurred in 87.87% of eyes of pre-eclampsia patients and in 94% of eyes of MHT patients. Subretinal drusenoid deposit-like lesions occurred in 28.57% of all eyes with SRD, in 32.76% of eyes with SRD from the pre-eclampsia group, and in 23.40% of eyes with SRD from the MHT group. Vascular imaging suggested underlying choroidal ischemia in all patients (12 eyes) in which it was performed.

CONCLUSIONS

Choroidal ischemia may be the underlying mechanism of SDD-like lesions in patients with pre-eclampsia and MHT choroidopathy. These findings potentially are of utmost importance in understanding the mechanism of the reticular macular disease subtype of AMD. Reticular macular disease is characterized by the known association of choroidal insufficiency and SDD, with choroidal insufficiency postulated, but not proven, to be causative. Pre-eclampsia and MHT choroidopathy seems to be a model for lesions similar to SDD in AMD developing based on choroidal insufficiency and, as such, may offer further insights into the pathoetiologic features of SDD in AMD.

AMISH EYE STUDY: Baseline Spectral Domain Optical Coherence Tomography Characteristics of Age-Related Macular Degeneration

PURPOSE

To describe spectral domain optical coherence tomography (SD-OCT) findings in an Amish cohort to assess SD-OCT markers for early age-related macular degeneration (AMD).

METHODS

The authors performed a family-based prospective cohort study of 1,146 elderly Amish subjects (age range 50-99 years) (2,292 eyes) who had a family history of at least 1 individual with AMD. All subjects underwent complete ophthalmic examinations, SD-OCT using both Cirrus and Spectralis (20 × 20° scan area) instruments, fundus autofluorescence, infrared imaging, and color fundus photography. Spectral domain optical coherence tomography characteristics were analyzed in subjects with AMD (with and without subretinal drusenoid deposits [SDDs]) and normal healthy cohorts.

RESULTS

Participants' mean age was 65.2 years (SD ± 11). Color fundus photographic findings in 596 (53%) subjects (1,009 eyes) were consistent with AMD; the remaining 478 (43%) subjects showed no signs of AMD. The choroid was significantly thinner on OCT (242 ± 76 µm, P < 0.001) in those with AMD compared with those without (263 ± 63 µm). Subretinal drusenoid deposits were found in 143 eyes (7%); 11 of the 143 eyes (8%) had no other manifestations of AMD. Drusen volume (P < 0.001) and area of geographic atrophy (P < 0.001) were significantly greater, and choroid was significantly (P < 0.001) thinner in subjects with SDDs versus those without SDDs.

CONCLUSION

The authors describe spectral domain optical coherence tomography characteristics in an elderly Amish population with and without AMD, including the frequency of SDD. Although relatively uncommon in this population, the authors confirmed that SDDs can be found in the absence of other features of AMD and that eyes with SDDs have thinner choroids.

Association of imaging biomarkers and local activation of complement in aqueous humor of patients with early forms of age-related macular degeneration

Purpose

To investigate a possible correlation between established imaging biomarkers for age-related macular degeneration and local complement system activation, measured in aqueous humor (AH) of patients with early stages of age-related macular degeneration (AMD) and controls.

Methods

This analysis included prospectively acquired AH samples of 106 eyes (35 with early/intermediate AMD, 71 controls). The levels of complement protein 3 (C3), 4 (C4), 5 (C5); activation products of complement factor 3a (C3a) and Ba, C3b/iC3b; complement factors B, D, H, I (CFB, CFD, CFH, CFI); and total protein concentration were analyzed. Quantitative levels of complement factors were correlated to the presence of reticular pseudodrusen (RPD), the presence of hyperreflective foci (HRF), and total drusen volume (DV) graded on imaging by spectral-domain optical coherence tomography and using Spearman’s rank correlation test.

Results

DV correlated with C3b/iC3b (r = 0.285; P = 0.034), C3a (r = 0.200; P = 0.047), Ba (r = 0.262; P = 0.009), and C5 (r = 430; P = 0.005), and showed a tendency towards correlation with C3a (r = 0.198; P = 0.057). HRF correlated significantly with C5 (r = 0.388; P = 0.011) and RPD showed a tendency towards correlation with CFB (r = 0.196; P = 0.050).

Conclusion

In patients with early AMD, HRF and drusen parameters but not RPD show low to fair levels of correlation with local complement activation in patients’ AH. Better understanding of complement activation could provide some insights into the pathogenesis of AMD. Imaging biomarkers could be useful to identify suitable patients for future clinical trials with complement-modulating therapies.

Characteristics of Geographic atrophy in an elderly UK population-The Bridlington Eye Assessment Project (BEAP): a cross-sectional study (2002-2006)

BACKGROUND/OBJECTIVES

Geographic atrophy (GA) is a common cause of visual loss. The UK population prevalence is unknown. We studied GA prevalence, characteristics, and associations in an elderly UK population.

METHODS

Masked grading of colour fundus photographs from 3549 participants in the cross-sectional study of Bridlington residents aged ≥65 years. GA size, shape and foveal involvement were correlated with demography and vision.

RESULTS

GA was detected in 130 eyes (101 individuals) of 3480 participants with gradable images (prevalence 2.90%; 95% CI 2.39-3.52 either eye), was bilateral in 29/3252 subjects (0.89%, 95% CI 0.62-1.28) with bilateral gradable photos, with mean age of 79.26 years (SD 6.99, range 67-96). Prevalence increased with age, from 1.29% (95% CI 0.69-2.33) at 65-69 to 11.96% (95% CI 7.97-17.50) at 85-90 years. Mean GA area was 4.51 mm² (SD 6.48, 95% CI 3.35-5.66); lesions were multifocal in 47/130 eyes (36.2%; 95% CI 28.4-44.7). Foveal involvement occurred in 41/130 eyes (31.5%; 95% CI 24.2-40.0). In eccentric GA, mean distance from circumference to fovea was 671μm (SD 463; 95% CI 570-773). Older age (OR 1.10/year increase; 95% CI 1.06-1.14), RPD (OR 1.87; 95% CI 1.10-3.19) and large drusen/RPD ≥ 125 μm (OR 6.16; 95% CI 3.51-10.75) were significantly associated with GA in multivariate analysis. GA lesions (18/31 eyes; 58%; 95% CI 40.7-73.6) had U-shape configuration more frequently in RPD subjects than those without (9/99 eyes, 9.1%; 95% CI 4.66-16.6) (p = 0.0001).

CONCLUSION

GA, commonly solitary and eccentric, occurred in the perifovea. However, one third of GA eyes had foveal and bilateral involvement. Possible association of RPD with GA phenotype exists. Population multimodal imaging studies may improve understanding further.

Multi-focal electro-retinogram response following sub-threshold nano-second laser intervention in age-related macular degeneration

IMPORTANCE

The effect of sub-threshold nano-second laser (SNL) treatment on retinal function remains unknown.

BACKGROUND

SNL treatment has been studied as a potential intervention in intermediate age-related macular degeneration (iAMD). This study investigated the longitudinal effect of SNL treatment on retinal function.

DESIGN

This was a sub-study of the LEAD trial; a 36-month, multi-centre, randomized and sham-controlled trial.

PARTICIPANTS

Subjects with iAMD.

METHODS

Eligible participants were assigned randomly to receive SNL or sham treatment to the study eye at 6-monthly visits. Multi-focal electro-retinography (mfERG) was performed at each study visit from a study site. The mfERG responses were grouped into three regions (central, middle and outer rings) and compared between the SNL and sham group.

MAIN OUTCOME MEASURES

mfERG P1 response amplitude and implicit time.

RESULTS

Data were collected from 50 subjects (26 in the SNL group, 24 in the sham group). At baseline, the P1 amplitudes of both the study eyes and the fellow eyes were similar between the groups at all rings. In the sham group, the P1 amplitude gradually decreased over time (P < .05). In the SNL group, there was an improvement in P1 amplitude which became statistically significant at the 36-month visit, detected in both the treated and fellow eyes at the central (P = .005) and middle ring (P = .007) but not at the outer ring (P = .070). No difference in P1 implicit time detected between the groups (P > .05).

CONCLUSIONS AND RELEVANCE

SNL treatment improved electro-physiological function. mfERG could be useful for monitoring AMD progression and evaluating the efficacy of SNL treatment.

Natural course of adult-onset vitelliform lesions in eyes with and without comorbid subretinal drusenoid deposits

PURPOSE

Adult vitelliform lesions (AVL) are associated with age related macular degeneration (AMD) and subretinal drusenoid deposits (SRDD). We evaluated the natural course of AVL, assessing the influence of SRDD on disease progression, visual function and incidence of macular atrophy (MA) and choroidal neovascular membranes (CNVM).

METHODS

A retrospective cohort study was conducted between January 2011 and March 2016. Demographic, clinical and imaging data from 26 consecutive AVL patients were analysed following case note review. Optical coherence tomography images were graded for SRDD and patients divided into those with/without SRDD. Outcomes included presenting/changes in best corrected visual acuity (BCVA) and incidence of MA/CNVM.

RESULTS

Mean age was 78.6 ± 7.6 years. Mean follow-up was 51.5 ± 25.6 months. Twelve patients (46.2%) had SRDD at presentation with 3 more (11.5%) developing them. Subjects with SRDD were older (mean 81.7 ± 6.1 years vs 74.3 ± 7.6 years, p = 0.010). Mean presenting BCVA was worse in SRDD eyes (0.39 ± 0.31 logMAR vs 0.19 ± 0.18 logMAR, p = 0.017). Eight of 15 patients with SRDD (53.3%) developed incident MA or CNVM; higher than those with no SRDD (1/11, 9.1%; p = 0.036). Two patients (7.7%) developed full thickness macular holes.

CONCLUSIONS

Patients with AVL and SRDD likely represent an advanced pathological stage or phenotype with worse visual outcome and higher risk of MA/CNVM. Possible overlap with AMD exists. Follow-up, counselling and provisions for early detection/treatment of complications should be made. Better classification including improved understanding of phenotypic and genetic variations with reference to comorbid diseases including AMD is required. Presence of SRDD in AVL offers a dichotomous classification, indicating risk of future MA/CNVM formation.

Complement factors and reticular pseudodrusen in intermediate age-related macular degeneration staged by multimodal imaging

Objective

Systemic activation of the complement system in intermediate age-related macular degeneration (AMD) is understudied. Moreover, links between the presence of reticular pseudodrusen (RPD) and systemic complement dysregulation have not been studied. The aim of this study was to determine if there is a difference in plasma complement factor levels in intermediate AMD compared with controls, and if complement levels are related to the presence of RPD.

Methods and analysis

Levels of complement factors C1q (µg/mL), C4 (µg/mL), C2 (µg/mL), Mannose Binding Lectin (ng/mL), C4b (µg/mL), C3 (µg/mL), factor B (µg/mL), factor D (µg/mL), properdin (µg/mL), C3a (ng/mL), iC3b/C3b (ng/mL), Ba (ng/mL), factor H (µg/mL), factor I (µg/mL), C5 (µg/mL), C5a (pg/mL) and SC5b-9 (ng/mL) were measured in plasma.

Results

109 cases and 65 controls were included in the study. Thirty-nine (36%) cases had RPD. Significantly lower systemic levels of: C1q (OR 0.96, 95% CI 0.94 to 0.98), factor B (OR 0.98, 95% CI 0.96 to 0.99), iC3b/C3b (OR 0.97, 95% CI 0.95 to 0.98), factor H (OR 0.99, 95% CI 0.98 to 0.99), factor I (OR 0.83, 95% CI 0.77 to 0.89) and C5 (OR 0.94, 95% CI 0.90 to 0.98) were found in cases versus controls. Significantly elevated levels of: C2 (OR 1.29, 95% CI 1.07 to 1.59), C3a (OR 1.03, 95% CI 1.01 to 1.05) Ba (OR 1.03, 95% CI 1.01 to 1.05) and C5a (OR 1.04, 95% CI 1.02 to 1.07) were found in cases versus controls. Systemic levels of complement factors measured were not related to the presence of RPD.

Conclusions

Levels of several systemic complement pathway factors were found to be altered in intermediate AMD. Systemic levels of complement factors were not related to RPD.

Subretinal Drusenoid Deposits in the Elderly in a Population-Based Study (the Montrachet Study)

Purpose

The aim of this study was to investigate the prevalence of subretinal drusenoid deposits (SDD) and to identify associated factors in an elderly population.

Methods

The participants of the population-based Montrachet study underwent an exhaustive ophthalmologic examination, including color fundus photography and macular spectral domain-optical coherence tomography (SD-OCT), coupled with infrared reflectance imaging. The presence of SDD and other age-related macular degeneration lesions, according to the European Eye Epidemiology SD-OCT classification of macular diseases, and subfoveal choroidal thickness were recorded. Moreover, the association of SDD and both clinical and demographic factors as well as plasma levels of vitamin E and lutein/zeaxanthin (L/Z) were analyzed.

Results

The mean age of patients was 82.3 ± 3.8 years and 62.7% were female. The prevalence of SDD was 18.1% (n = 205) in the subjects with at least one eye interpretable (n = 1135). In multivariate analysis, SDD was positively associated with increasing age (OR, 4.6; 95% CI, 2.8-7.7; P < 0.001 for subjects aged >85 years), female sex (OR, 1.7; 95% CI, 1.2-2.4; P = 0.005), and plasma L/Z level (OR, 1.2; 95% CI, 1.0-1.5; P = 0.039), and negatively associated with lipid-lowering drugs use (OR, 0.5; 95% CI, 0.3-0.9; P = 0.014 for statin medications) and subfoveal choroidal thickness (OR, 0.8; 95% CI, 0.7-0.9; P = 0.002).

Conclusions

The prevalence of SDD was high in subjects older than 75 years, more frequent in women, and was associated with a thinner choroid. The association with lipid-lowering drugs deserves further investigation.